162P Responses to EGFR TKIs and ALK TKIs in advanced NSCLC patients harboring concomitant EGFR and ALK alterations

Background: Previous studies indicated that Epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement are mutually exclusive in non-small cell lung cancer (NSCLC). However, cases diagnosed with concomitant EGFR and ALK alterations has been occasionally reported. This study aimed to assess the prevalence of this small subset patients and optimize clinical management. Methods: We retrospectively collected clinical outcomes of 29 cases who had concomitant EGFR and ALK alterations from 5816 lung cancer patients tested EGFR mutation and ALK rearrangement between 2011–2017 in the Shanghai Chest Hospital. Meanwhile, we identified 103 cases harboring double positive mutations from a literature search. Of these 132 cases, 81 patients received EGFR tyrosine kinase inhibitor (EGFR-TKI) or ALK-TKI treatment. Results: The frequency of EGFR/ALK co-alterations was 0.5% (29/5816; 95%CI:0.3%-0.7%) in NSCLC in our center. For all 132 cases, there is a prevalence of women (67 female, 46 male, 19 not reported), Asian (87Asian, 44 Caucasian, 1 not reported) and never smoker patients (77 never smokers, 21 smokers, 34 not reported). We divided the patients into three groups according to EGFR or ALK TKIs treatment: A: single EGFR TKI group (36 cases), B: single ALK TKI group (14 cases) and C: both TKIs (31 cases). All patients were assessed for TKIs responses. The disease control rate (DCR) of EGFR-TKI was 81.5%, whereas the DCR of ALK-TKI was 89.1%. The median PFS of three groups were 12.4, 15.9 and 24.1months, respectively (P = 0.02). The PFS of group A and C had statistically sigificant difference (P = 0.006). But the PFS of group A and B, B and C did not have statistical significance (P = 0.338, P = 0.335). Conclusions: EGFR mutations and ALK rearrangement do coexist in NSCLC. In cases with double positive mutations, our preliminary study suggests that PFS of those who received double TKIs is longer than those who received only one TKI. Combination of both TKIs might be an appropriate choice. The result of the study indicates that ALK TKI might be preferentially administered when TKI is initiated as first-line treatment. Legal entity responsible for the study: Wang shuyuan Funding: Has not received any funding Disclosure: All authors have declared no conflicts of interest.